Further studies on the heat production and effective lower critical temperature of early-weaned pigs under commercial conditions of feeding and management

1984 ◽  
Vol 39 (2) ◽  
pp. 283-290 ◽  
Author(s):  
K. J. McCracken ◽  
R. Gray
Keyword(s):  
Critical Temperature ◽  
Heat Production ◽  
Thermal Conductance ◽  
Open Circuit ◽  
Weaned Pigs ◽  
Respiration Chamber ◽  
Lower Critical Temperature ◽  
The Mean ◽  
The Difference ◽  
Practical Implications

ABSTRACTIn two separate experiments pigs were weaned at 14 or 28 days and heat production was determined in an open-circuit respiration chamber at temperatures above and below the lower critical temperature (Tcl) at intervals during the post-weaning period.With 14-day weaned pigs the mean 24 h heat production above Tc1 averaged 267, 328, 474 and 554 kJ/h per m2 at 3, 9, 15 and 21 days post weaning respectively. The mean thermal conductance (H/AT, kJ/h per m2 per °ΔT, where H is total heat production, m2 is the surface area calculated as 0·097 M kg0·633 and °Δ is the difference between rectal temperature, taken at 39°, and air temperature) below TC1 was calculated as 20·5, 20·1, 23·1 and 24·2 at 17, 23, 29 and 35 days of age respectively and the corresponding values for Tc1 were 25·9, 23·0, 18·4 and 16·0°C.With 28-day weaned pigs the mean 24 h heat production above Tc1 averaged 280, 361 and 445 kJ/h per m2 at 3, 9 and 15 days post weaning. The calculated values for H/ΔT were 19·7, 20·8 and 21·6 and the corresponding values of Tcl were 24·8, 21·7, and 18·8°C at 31, 37 and 43 days of age respectively.The results are discussed in relation to previous studies on 10-day and 28-day weaned pigs and in relation to the practical implications for pigs weaned into controlled-environment accommodation.

scholarly journals Studies on diurnal variations of heat production and the effective lower critical temperature of early-weaned pigs under commercial conditions of feeding and management

1980 ◽  
Vol 43 (2) ◽  
pp. 321-328 ◽  
Author(s):  
K. J. McCracken ◽  
B. J. Caldwell
Keyword(s):  
Critical Temperature ◽  
Heat Production ◽  
Thermal Conductance ◽  
Open Circuit ◽  
Respiration Chamber ◽  
Mean Values ◽  
Maximum Value ◽  
Lower Critical Temperature ◽  
The Mean ◽  
The Difference

1. The heat production of groups of pigs, weaned at 10 d of age, was determined in an open-circuit respiration chamber at various ages between 10 and 33 d at temperatures above and below the lower critical temperature (Tcl).2. The heat production was lowest on the second or third day post weaning when pigs were given feed increasing by 25 g/pig per d from day 2. There was a marked diurnal pattern in heat production, the lowest values being recorded between 24.00 and 08.00 h.3. The mean thermal conductance (H/ΔT, kJ/h per m2 per °ΔT, where His total heat production, m2 is the surface area calculated as 0.097 W kg0.633 (Brody, 1945) and °ΔTis the difference between rectal temperature, taken as 39°, and air temperature) below Tcl was calculated as 18.0, 16.9, 18.5 and 21.2 respectively at 10, 17, 24 and 31 d of age. Maximum values of H/ΔT obtained during feeding periods were. on average, 4.5 kJ/h per me per °ΔT higher than the mean values.4. The maximum value for Tcl during the immediate post-weaning period was 25.9°. The mean Tcl at 17, 24 and 31 d were respectively 21.7, 18.4 and 18.6° for pigs fed almost to appetite.

Effect of confinement in a respiration chamber and changes in temperature and plane of nutrition on heat production of 25 kg pigs

1980 ◽  
Vol 95 (1) ◽  
pp. 123-133 ◽  
Author(s):  
R. Gray ◽  
K. J. McCracken
Keyword(s):  
Carbon Dioxide ◽  
Energy Intake ◽  
Heat Production ◽  
Environmental Temperature ◽  
Normal Range ◽  
Respiration Chamber ◽  
The Third ◽  
Lower Critical Temperature ◽  
The Mean ◽  
Range Of Variation

SummaryA closed-circuit respiration chamber was used to study (a) the effect of confinement in a chamber on the heat production of pigs already accustomed to restraint in a metabolism cage; (b) changes in daily heat production of pigs following a reduction in the energy intake; and (c) the effect of increasing or decreasing the environmental temperature.An automatically recharged version of the oxygen burette used by Waring & Brown (1965) is described. During tests of the chamber and burette system the mean recoveries of carbon dioxide and oxygen were, respectively, 0·994 and 0·995.It is concluded that measurements of heat production on the first day of confinement were within the normal range of variation and provided valid estimates of energy expenditure.The minimum value for the respiratory quotient (RQ) occurred on the third day following a reduction in energy intake, and it is concluded that the direct effect of previously ingested nutrients was eliminated by the third day. However, there appeared to be a further decline in heat production until 6–7 days following the reduction in energy intake.The heat production of singly caged pigs fed almost to appetite was similar at 22 and 29 °C. Heat production increased at 15 °C, indicating that this was below the lower critical temperature of fed 25 kg pigs. The response of heat production to the low temperature continued for at least 18 days. Variations in heat production between animals and litters were as high as 15% in three experiments.

The heat production of oiled mallards and scaup

1973 ◽  
Vol 51 (1) ◽  
pp. 27-31 ◽  
Author(s):  
E. H. McEwan ◽  
A. F. C. Koelink
Keyword(s):  
Critical Temperature ◽  
Metabolic Rate ◽  
Ambient Temperature ◽  
Heat Loss ◽  
Heat Production ◽  
Normal Values ◽  
Thermal Conductance ◽  
Water Repellency ◽  
Regression Analyses ◽  
Lower Critical Temperature

A measure of the thermal conductance of the plumage of normal and oiled ducks was determined from regression analyses that related metabolic rate and ambient temperature. The heat loss of heavily oiled mallards and scaup was 1.7 and 2 times greater than their normal values, respectively. Oiling not only tended to increase the basal heat production, but also shifted the lower critical temperature from 12 to 25C. Attempts to rehabilitate the scaup after oiling and cleaning were rarely successful because of plumage deterioration and the loss of water repellency.

Thermoregulation in the only nocturnal simian: the night monkey Aotus trivirgatus

1981 ◽  
Vol 240 (3) ◽  
pp. R156-R165 ◽  
Author(s):  
Y. Le Maho ◽  
M. Goffart ◽  
A. Rochas ◽  
H. Felbabel ◽  
J. Chatonnet
Keyword(s):  
Critical Temperature ◽  
Metabolic Rate ◽  
Response Pattern ◽  
Thermal Environment ◽  
Resting Metabolic Rate ◽  
Thermal Conductance ◽  
Open Circuit ◽  
The Body ◽  
Thermoneutral Zone ◽  
Lower Critical Temperature

The night monkey, a tropical monkey, is the only nocturnal simian; its thermoregulation was studied for comparison with other nocturnal or diurnal primates and other tropical mammals. Resting metabolic rate was 2.6 W (closed-circuit method) and 2.8 W (open-circuit method), 24 and 18% below the value predicted from body mass. The thermoneutral zone was very narrow; the lower critical temperature (LCT) was 28 degrees C and the upper critical temperature (UCT) was 30 degrees C. The body temperature (Tb) was at its minimum (38 degrees C) at an ambient temperature (Ta) of 25 degrees C, thus below the LCT. At low Ta, the increase in metabolic rate (MR) was smaller than predicted by the Scholander model, since MR intersected to a Ta 13 degrees C above Tb when extrapolated to MR = 0; this was attributed to a decrease of body surface area by behavior. The thermal conductance at the LCT was low: 2.3 W . m-2 . degrees C-1. Above the UCT, panting was the major avenue of heat loss. The response pattern of nocturnal habits, low resting metabolic rate, low thermal conductance, and panting in the night monkey, unique among simians, is found in many other mammals of tropical and hot desert habitats; it may be considered as an alternative adaptation to the thermal environment.

Oxygen cost of voluntary hyperventilation

1959 ◽  
Vol 14 (2) ◽  
pp. 187-190 ◽  
Author(s):  
John F. Murray
Keyword(s):  
Carbon Dioxide ◽  
Technical Assistance ◽  
Respiratory Exchange Ratio ◽  
Minute Volume ◽  
Open Circuit ◽  
Oxygen Cost ◽  
Voluntary Hyperventilation ◽  
The Mean ◽  
The Difference ◽  
Circuit Technique

The oxygen cost of voluntary hyperventilation was measured using an open circuit technique with three variations, unaided hyperventilation of air, breathing through an increased dead space and adding carbon dioxide to the inspired air. After a given minute volume had been maintained for 10 minutes, the oxygen consumption was the same with the three methods, in spite of marked differences in the respiratory exchange ratio and volume of carbon dioxide produced. The mean oxygen cost for all three methods was 3.2 ml/l. of ventilation. The amount of nonmetabolic oxygen stored during the first minute of hyperventilation was estimated by finding the difference between the oxygen uptake during the 1st minute and the amount utilized when a steady state is reached. It is concluded that the effects of changing oxygen stores are minimal after 10 minutes of hyperventilation and probably after 5 minutes, at a constant minute volume. Note: (With the Technical Assistance of Liana Nebel) Submitted on June 27, 1958

scholarly journals Laboratory Metabolism of Incubating Semipalmated Plovers

The Condor ◽  
2006 ◽  
Vol 108 (4) ◽  
pp. 966-970
Author(s):  
Mark Williamson ◽  
Joseph B. Williams ◽  
Erica Nol
Keyword(s):  
Critical Temperature ◽  
Metabolic Rate ◽  
Breeding Season ◽  
Basal Metabolic Rate ◽  
Low Temperatures ◽  
Thermal Conductance ◽  
Basal Metabolism ◽  
The Arctic ◽  
Lower Critical Temperature ◽  
Metabolic Data

Abstract Abstract The Semipalmated Plover (Charadriussemipalmatus), anarctic-nesting migratory shorebird, regularlyencounters low temperatures during the breedingseason. We measured the basal metabolism of adultsduring incubation at Churchill, Manitoba, Canada todetermine basal metabolic rate (BMR),lower critical temperature(Tlc), total evaporative waterloss (TEWL), and dry thermal conductance(Cm). BMR and Tlcwere 47.4 kJ day−1and 23.3°C, respectively, TEWL was2.5 mL H2O−d,and Cm was1.13 mW g−1 °C−1.Measured BMR and Tlc were consistentwith high values found for other shorebird speciesbreeding in the Arctic, while Cm was18% higher than predicted from allometricequations. These metabolic data suggest thatSemipalmated Plovers are adapted to balance therequirements of incubation against energetic andthermoregulatory demands in the Arctic, especiallyin harsh early breeding season conditions.

Comparison of feeding behaviour and performance of weaned pigs given food in two types of dry feeders with integrated drinkers

1999 ◽  
Vol 68 (1) ◽  
pp. 35-42 ◽  
Author(s):  
M. Laitat ◽  
M. Vandenheede ◽  
A. Désiron ◽  
B. Canart ◽  
B. Nicks
Keyword(s):  
Feeding Behaviour ◽  
Feeding Activity ◽  
Weaned Pigs ◽  
Multifactor Analysis ◽  
Daily Water ◽  
The Mean ◽  
The Difference ◽  
And Performance ◽  
Almost All ◽  
Type V

AbstractPerformance of 80 (tests 1 and 2) or 60 (tests 3 and 4) weaned pigs were compared when using ‘Tubetype’ feeder (T), allowing the animals to mix meal and drinking water, or another type (V) where drinking and eating places are separated. The difference in growth rate was not significant but the mean daily water consumption (1 per pig per day) was higher with T than with V in each test but significantly only in tests 1 and 3 (1·84 v. 1·40, and 2·11 v. 1·26, P < 0·01).Feeding behaviour was assessed during tests 2 and 4. Multifactor analysis of variance revealed effects (P < 0·01) of feeder, group size and period of the day on the occupation time and the average number of animals using the feeders simultaneously. These two variables were higher for V than for T (test 2: 23·4 per 24 h v. 21·5 per 24 h and 4·5 v. 3·7, P < 0·05; test 4: 20·0 per 24 h v. 18·2 per 24 h, P< 0·01). In each test, both feeders were used for a longer time and by more piglets during the ‘day’ than during the ‘night’ (P < 0·01). When grouping 40 pigs, animals used both feeders during almost all the day period (V: 15·9 per 16 h and T: 15·8 per 16 h). During the night period, this was only true with V (V: 7·4 per 8 h; T: 5·8 per 8 h). The use of feeder V in crowded conditions thus prevented preferential diurnal feeding activity, commonly described in pigs. In conclusion, even if productivity is not affected, feeding behaviour and thus eventually welfare are influenced by the type of feeder, especially with high numbers of animals.

Activity and energy expenditure in laying hens: 3. The energy cost of eating and posture

1976 ◽  
Vol 87 (1) ◽  
pp. 85-88 ◽  
Author(s):  
M. Van Kampen
Keyword(s):  
Energy Expenditure ◽  
Spontaneous Activity ◽  
Heat Production ◽  
Energy Cost ◽  
Laying Hens ◽  
The Mean ◽  
Per Se ◽  
The Difference

SummaryThe influence of standing, spontaneous activity and eating on heat production was determined.The extra heat production of standing is negatively correlated with the length of standing period. In a short standing period of 30 min the associated activity, pecking against the respirometer wall and fluffing the feathers, was high and the heat production was increased by 25% compared with that during sitting. After standing for 1½ h spontaneous activity was very low and the difference in heat production between the standing and sitting bird was reduced by 9%.During eating the heat production increased by an average of 37% (range 11–68%); this was due mainly to the act of eating per se and not to the work of digestion.The mean energy cost of eating was calculated to be 143 J/kg0·75/min spent eating.

Energy cost of eating long hay, straw and pelleted food in sport horses

1995 ◽  
Vol 61 (3) ◽  
pp. 581-588 ◽  
Author(s):  
J. Vernet ◽  
M. Vermorel ◽  
W. Martin-Rosset
Keyword(s):  
Wheat Straw ◽  
Energy Cost ◽  
Dry Matter ◽  
Energy Requirement ◽  
Ingestion Rate ◽  
Open Circuit ◽  
Metabolizable Energy ◽  
Long Form ◽  
The Mean ◽  
The Difference

AbstractSix sport horses were given 1·26 times the measured maintenance energy requirement (MEm) from each of the four following diets: H1, meadow hay in the long form (organic matter digestibility OMD = 0·541); HMI, 700g/kg the same hay and 300 g/kg pelleted maize; HSBPI, 600g/kg hay and 400g/kg pelleted dehydrated sugar-beet pulp; SCFI, 500g/kg wheat straw and 500g/kg pelleted compound food (experiment 1). In experiment 2, eight sport horses were equipped with a portable device for recording feeding behaviour and fed at 1·31 MEm diet HI (meadow hay in the long form: OMD = 0·574).Circadian energy expenditure (EE) of horses was determined by indirect calorimetry using two large open-circuit respiration chambers. Horses were continuously standing. Increase in metabolic rate (IMR) during eating was calculated from the difference between the mean EE obtained during each eatingperiod and the corresponding resting EE. The mean daily ingestion rate of hay H2 amounted to 148 (s.d. 27)mg dry matter per kg metabolic body weight per min. IMR during the two main meals averaged 0·388 (s.d. 0·059) and was not significantly different between diets H1, H2, HM1 and SCF1. Expressed per kg dry matter intake, energy cost of eating (ECE) was similar for diets H2, H1 and SCF1 but significantly lower for HSBP1 and HM1 (P<0·05). ECE of simple foods was calculated from those of the diets and of hay: proportionately 0·010, 0·042, 0·102 and 0·285 metabolizable energy intake for pelleted maize, pelleted SBP, long hay and wheat straw, respectively.

scholarly journals The energy cost of standing and lying in adult cattle

1973 ◽  
Vol 30 (2) ◽  
pp. 207-210 ◽  
Author(s):  
J. E. Vercoe
Keyword(s):  
Heat Production ◽  
Energy Cost ◽  
Fast Response ◽  
Short Term ◽  
Time Intervals ◽  
Adult Cattle ◽  
Respiration Chamber ◽  
Gas Exchanges ◽  
The Difference ◽  
Over Time

1. Gas exchanges on eleven steers with a mean weight of 273 kg, fasted for 96 h, were obtained over time intervals of 5·76 min in a confinement-type respiration chamber, when the animals were either standing of lying, or engaged in the act of standing or lying.2. In all, 751 observations were analysed and these included twenty-four associated with the act of standing, forty-eight with the act of lying and the remainder approximately equally divided between standing and lying.3. When lying, the heat production was 72·2 kJ (17·2 kcal)/kg fasted weight per 24 h and when standing, 85·7 kJ (20·5 kcal)/kg fasted weight per 24 h; an increase when standing of 18·7%. The double act of standing and lying was associated with an increase in heat production of 11·3 kJ (2·7 kcal)/100 kg fasted weight and while the act of standing was energetically more costly than the act of lying, the difference between the two was not significant.4. The results are discussed in relation to earlier estimates.5. Confinement-type respiration chambers of the type described by Turner & Thornton (1966), which have a fast response time and monitor the changes in chamber air frequently, are ideally suited to the detection of short-term changes in metabolic rate such as occur with changes in posture.

Sign in / Sign up

Export Citation Format

Share Document